you should start seeing the logs restoring all missing nuget packages, then compile the code.

Associate your database connection string to the Function App. To do that, click on the top link “Function app settings” then click the button “Go to App Service Settings”
It will open your Function App settings page, then click on Data Contentions, Add
once you successfully added a connection called “SqlConnection“, close the views and navigate back to your function using the breadcrumbs.

Click on your function named “HttpTriggerSqlDatabase”, copy the snippet bellow.